1. Field of Invention
This invention relates to a timer operated throttle closing device for drag racing vehicles. In particular, this throttle closing device automatically senses the initiation of the race and automatically closes the throttle after a predetermined period of time has elapsed, and after a second period of time has elapsed automatically releases the throttle closure device.
2. Description of the Prior Art
Throttle override devices have been developed in the past for the purposes of protecting engines from dangerous conditions such as excessive speed or low engine oil pressure. Hofer U.S. Pat. No. 2,840,064 discloses a device which operates off of a hydraulic servomotor to measure both engine speed and engine oil pressure. Hajime Ariga, et al. U.S. Pat. No. 3,517,653 teaches a device which will selectively interrupt the idle fuel circuit of a carburetor of an engine when the engine is driven by outside inertia such as when coasting down, and also, when the engine is a run on state.
Krueger et al. U.S. Pat. No. 4,362,138 teaches a governor type device which automatically overrides the throttle linkage to reduce the fuel supply to a carburetor for purposes of fuel economy.
In connection with drag racing vehicles Corbi U.S. Pat. No. 4,524,741 discloses a throttle release device for use on drag racing cars to manually set the maximum throttle opening at the commencement of a drag race.
What is needed is a device which automatically overrides manual throttle control to close the throttle for a selected period of time during the drag race.
Controlled drag racing can be briefly described as follows: in drag racing competition is divided into several eliminator categories in which the competition is against a designated index, usually time, in addition to the other vehicle. In Super Gas eliminator this index is 9.90 seconds. The object is to run the course in exactly the index time, every run, and still be the first car across the finish line. Running quicker than the index is called a breakout and results in a loss or being eliminated. This rule keeps competing cars more evenly matched. Most competitors build an engine and chassis combination that is capable of running 0.4 or 0.5 seconds quicker than the index. This results in a harder launch and quicker times at the 60 foot point from the start. Launch and 60 foot times are the major factor in determining the winner of a contest in these elimination races.
To get the car to run the course in exactly the index time, the driver must slow the car down near the end of the track. Various types of throttle stops or restrictor devices have been built. Most operate off of transmission hydraulic pressure to activate a cylinder on the throttle. Usually they are activated when the transmission is shifted into high gear. The throttle is then pulled to some position less than wide open throughout high gear.
The invention herein is for a throttle stop that is activated by a timer adjustable to thousandths of a second. The timer is activated on the launch and can be adjusted from the driver's seat. After activation the timer will activate the hydraulic cylinder on the throttle at some preset time. This activation will last for a period that is also predetermined. The unit will then release the throttle back to the wide open position.
The advantage of this system is that the throttle will not be partially closed all the way through high gear. It would be closed more but at a point closer to the finish line. Also, the system operates on normal compressed air available at any service station.